Azo-dyestuffs of the pyrazolone series and process of making same



N Drawing. Application filed December '16, 1927, serialrfid QiOfilffaiidin sas'z eriaaaiieamba 25 61 Patented Oct. 20, 1931 i UNIT-ED STATESGUILLAUME 1m MoN'rMoLLIN, or nAsnL AN SWITZERLAND, AssIeNons T0 SOCIETYBASEL, SWITZERLAND- AZO-DYESTUFFS or THE PYRAzoLonE snainskivb tainbeside the diazo-group at least one substituent in the aryl nucleus,with 3-methyl 5- pyrazolone. The dyestuffs thus obtained correspond tothe general formula:

oHa-o'=N NH arylN=N-C-C I f[ (l in which the aryl nucleus contains'atleast one substituent. Quite a number of these dyestuffs areCharacterized by a surprisingly excellent affinity for acetyl-celluloseor celluyellow to orange-red non-phototrop tints. Especially fast tolight are those dyestufiis,

which derive from o-nitrodiazo-compounds,

such as the diazo-compounds of o-nitraniline, 4-chloro-2-nitraniline,4-alkoxy-2-nitraniline, and the like. Due to the solubility of the newdyestuffs in alcohol and the various organic liquids the products mayalso.

be employed for the manufacture of dyed lacquers of artificial ornatural origin which, according to the diazotizing component used, aredyed in green-yellow to red-orange and violet tints, When dry the newdyestuffs form powders the color of which, according to the composition,may be yellow, orange,

red or violet. They are insoluble in water,

but soluble in alcohol "with yellow, orange,

red or violet coloration. Q

Example A" dia z'o-solution obtained in the usual manner from 15.2 partsof 4-amino-3-nitrol-methyl-benzene is poured into a solution of 10 partsof 3-methyl-5-pyrazolone to which" 30 parts of crystallized sodiumacetate have been added. The dyestufl' which is immediately'precipitated'is filtered by suction and washed. When dry it forms ayellowpowder which is insoluble in water, but soluble in alcohol withyellow coloration. In aqueous suspension it dyes acetate silk yellowtints; very fast to light. This dyestuff dyes also" lacquers in yellowtints very" fast to light or A onnmcan mpus'rny INX'BASLE} or The 'fe'fula of" A 'd'iazo' solution obtainea in the asual manner from 19.7 partsof amino-azobenzene 1s poured into a golution" of lOparts'of 3;-methyl-5-pyrazolonetog'whicli -30 parts er crystallized sodiumacetateliavebeeri addedf The :dyestuff which is {immediately precipi- Htat'ed is filtered by suction anuwashed: Whli the product is v i dry itforms an orangelpowderwhichjs soluble" in'fwatr; but soluble; inalcohol' with orange coierauen; It dy saeetyr cellu se in orange-yellowtints and may be use'd f t-lie manufacture ofio'range coloredZapon'lacquers which are fast .to lighti T'lie formula of thenewprodiict is very probably:

l the we? i 1; Process for the manufacture ojfnew azo "I so dyestuffs,consistingin .coupli'ngsuch aro- 1 matlc, u'ns'ulphonated..diazoecompounds B' of 2. Process for the manufactureof newazodyestuffs,consisting in coupling such aromatic, 'unsulphonated diazo-compounds -ofthe benzene series, which contain in the aryl nucleus besides thenitro-group in ortho positionto the diazo-group a substituent in 4-position. to the diazo-g roup, with 3-methyl-5 pyrazolone. i

3. Process 4-.amino-3-nitro 1-methylbenzene with 3- methyl-5-pyrazolone.

. I V for the manufacture of newazo- I dyestuffs, consistingin couplingdiazotizedl the pyrazolone series corresponding with the generalformula:

OHa- =N wherein R is an aromatic unsulfonated nucleus of the benzeneseries, which contains in the o-gosition to the diazo-groupa'nitro-groupf w ich products, when dry, form yellow pow ders, insolublein water, but soluble in alcohol with similar coloration, and which dyeacetyl cellulose and lacquers also similar tints which are very fast,especially yery fast to light. r I

As new products theazo-dyestuffsof the pyrazolone series correspondingwith the general formula:

wherein R is an aromatic unsulfonated nucleus of the benzene series,which contains besides the nitro-group in ortho-position to thediazo-group a- 'substituent in the 4-position to the diazo-group, whichproducts, when dry, form yellow powders, insoluble in water, but solublein alcohol with similar coloration. and. which dye acetyl cellulose andlacquers also similar tints which are very fast, especially very fast tolight. I

6. As a new product, theazo-dyestufi'of the pyrazolone seriescorresponding with the formula: r

(IJHQ which product, when dry, forms a yellow powder, insoluble inwater, but soluble in alcohol with similar coloration and which dyesacetyl cellulose and lacquers also a similar tint, which is Very fast,especially very fast to light; r

'In witness whereof we have hereunto signed our names this 3rd day ofDecember GUILLAUME DE MONTMOLLIN. MAXSCHMID. 4.

